Chapter 4

warmersafternoonNetworking and Communications

Oct 23, 2013 (4 years and 15 days ago)

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© Prentice Hall 2002

4.
1

CHAPTER 4

Telecommunications &
Networking


© Prentice Hall 2002

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TELECOMMUNICATIONS:
Communications (both voice and data)
at a distance


NETWORKING:
Electronic linking of
geographically dispersed devices

*

TELECOMMUNICATIONS &
NETWORKING


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THE NEED FOR NETWORKING


SHARING OF TECHNOLOGY RESOURCES


SHARING OF DATA


DISTRIBUTED DATA PROCESSING AND
CLIENT/SERVER SYSTEMS


ENHANCED COMMUNICATIONS,
INCLUDING ELECTRONIC DATA
INTERCHANGE
(EDI)

AND ACCESS TO
THE INTERNET

*


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KEY ELEMENTS OF
TELECOMMUNICATIONS & NETWORKING


ANALOG SIGNALS:
Continuous
waveform, passes thru system. Example:
voice communications


DIGITAL SIGNALS:
Discrete waveform
two discrete states (1
-
bit & 0
-
bit, on /
off pulse).
Data communication. Uses
modem to translate analog to digital, digital
to analog

*




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MODEM


ABBREVIATION FOR
MO
DULATOR/
DE
M
ODULATOR


DEVICE THAT CONVERTS DATA
FROM DIGITAL FORM TO ANALOG
FORM TO BE SENT OVER ANALOG
TELEPHONE NETWORK
(RECONVERTS DATA AFTER IT HAS
BEEN TRANSMITTED)

*


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SPEED OF TRANSMISSION


BANDWIDTH:
Difference between
highest and lowest frequencies (cycles per
second) that can be transmitted on a
particular medium; a capacity measure


HERTZ:
Cycles per second


BAUD:
Signals sent per second


BITS PER SECOND

(bps):

Common measure

*


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TYPES OF TRANSMISSION LINES


PRIVATE, OR DEDICATED, LINES


SWITCHED LINES






SIMPLEX TRANSMISSION


HALF
-
DUPLEX TRANSMISSION


FULL
-
DUPLEX TRANSMISSION

*


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TRANSMISSION MEDIA


TWISTED PAIR


COAXIAL CABLE:
Baseband and
broadband


WIRELESS:
Cordless phone, cellular
phone, wireless LAN, infrared devices


SATELLITE:
Microwave, line of sight



FIBER OPTICS

*


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ORBITING SATELLITES

UPLINK

MICROWAVE
TRANSMISSION

DOWNLINK


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NEW SATELLITES


OVER A DOZEN NEW PROJECTS
PROPOSED


LOW EARTH ORBIT
(LEO)

SATELLITES:
Only 400 to 1000 miles
above the earth, compared to
geosynchronous satellites at 22,000 miles
above the equator. 1,700 satellites to be
launched by 2006

*


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NEW SATELLITES


IRIDIUM:
66 satellites offered mobile
telephony, paging, and data communications.
Bankrupt by 1999.


TELEDESCIC:
Will include 288 LEO to
provide low
-
cost, high
-
speed Internet access,
networking, teleconferencing

*


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TELECOMMUNICATIONS
TRANSMISSION SPEEDS


Twisted pair
-

voice telephone

14.4 kbps
-
56 kbps


Twisted pair
-

conditioned


56 kbps
-

144 kbps


Twisted pair
-

LAN



4 mbps
-

100 mbps


Coaxial cable
-

baseband


10 mbps
-

2 gbps


Coaxial cable
-

broadband


10 mbps
-

550 mbps


Radio frequency wireless LAN

1 mbps
-

11 mbps


Infrared light wireless LAN


4 mbps
-

16 mbps


Microwave / Satellite


64 kbps
-

100 mbps


Fiber optic cable




100 mbps
-

100 gbps

*


© Prentice Hall 2002

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TOPOLOGY OF NETWORKS


BUS TOPOLOGY


RING TOPOLOGY


STAR TOPOLOGY


TREE, OR HIERARCHICAL,
TOPOLOGY


MESH TOPOLOGY


MORE COMPLEX TOPOLOGIES

*


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NETWORK TYPES


COMPUTER
TELECOMMUNICATIONS NETWORK


PRIVATE BRANCH EXCHANGE
(PBX)

NETWORK


LOCAL AREA NETWORK
(LAN)

*


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NETWORK TYPES


BACKBONE NETWORK


WIDE AREA NETWORK
(WAN)


INTERNET

*


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LOCAL AREA NETWORKS


CONTENTION BUS NETWORK:
Uses

CSMA/CD

protocol. Example: Ethernet


TOKEN BUS NETWORK:
Central to
Manufacturing Automation Protocol

(MAP)


TOKEN RING NETWORK:
Used in
LAN
; unidirectional data flow

*


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NEW LAN TECHNOLOGY


FAST ETHERNET:
Ethernet operating at
speeds up to 100 mbps


FIBER DISTRIBUTED DATA
INTERFACE
(FDDI)
:
Token ring
architecture delivered on a dual ring at
speeds up to 100 mbps

*


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BACKBONE NETWORKS


MIDDLE DISTANCE NETWORKS:
Interconnect
LANs

in a single organization
with each other and with the organization’s
WAN and Internet


EMPLOY HIGH
-
END
LAN

TECHNOLOGY, OFTEN OPERATING
AT 100 MBPS OR MORE

*


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HUB:
Simple device connecting one section of a
LAN to another


BRIDGE:
Connects two LAN segments when the
LANs use the same protocols


ROUTER, OR GATEWAY:
Connects two or
more LANs together. Networks may use different
protocols


SWITCH:
Connects more than two
LANs

that use
the same protocol into a backbone network


*



BACKBONE NETWORK
TERMINOLOGY


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WIDE AREA NETWORKS


DIRECT DISTANCE DIALING
(DDD)


WIDE AREA TELEPHONE SERVICE
(WATS)


LEASED LINE:
Most common, T
-
1 lines


SATELLITE:
C
-
Band, KU
-
Band


VALUE ADDED NETWORK
(VAN)


INTEGRATED SERVICES DIGITAL
NETWORK
(ISDN)

*


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VALUE ADDED NETWORK
(VAN)


DATA
-
ONLY, PRIVATE, NONREGULATED
TELECOMMUNICATIONS NETWORK
:
Uses packet switching


AN ORGANIZATION MAY CHOOSE TO
BUY SERVICES OF A
VAN

TO IMPLEMENT
ITS WIDE AREA NETWORK
(
WAN
)

*


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PACKET SWITCHING


INFORMATION DIVIDED INTO
PACKETS OF SOME FIXED LENGTH,
SENT OVER NETWORK SEPARATELY


PERMITS MORE EFFICIENT USE OF
THE NETWORK

*


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INTEGRATED SERVICES
DIGITAL NETWORK
(ISDN)


EMERGING SET OF INTERNATIONAL
STANDARDS


USING PUBLIC TELEPHONE NETWORK


EXTENSIVE NEW
TELECOMMUNICATIONS CAPABILITIES


SIMULTANEOUS TRANSMISSION OF
VOICE AND DATA OVER SAME LINE TO
TELEPHONE USERS WORLDWIDE

*





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USES OF ISDN


CUSTOMER SERVICE APPLICATION:
Customer’s records automatically sent to
service representative’s workstation when
customer calls in


SOLVES DIAL
-
IN PROBLEMS INTO
CORPORATE NETWORK FOR
TELECOMMUTERS, BRANCH
OFFICES

*


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NEW
WAN

AND
LAN

TECHNOLOGY


ASYNCHRONOUS TRANSFER MODE
(ATM)
:
Switching technology employing
fast packet switching. Emerging standard for
broadband ISDN. Speeds from 1.544 mbps
to 622 mbps. Represents the future for both
LANs and WANs

*


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PROTOCOL

RULES & PROCEDURES

TO GOVERN TRANSMISSION

BETWEEN COMPONENTS

IN A NETWORK


*


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NETWORK PROTOCOLS


OPEN SYSTEMS INTERCONNECTION

(OSI)
:

Reference model, emerging standard


TRANSMISSION CONTROL PROTOCOL /
INTERNET PROTOCOL
(TCP/IP)
:

Standard used on
the Internet


SYSTEMS NETWORK ARCHITECTURE

(SNA)
:

IBM
standard


FILE TRANSFER PROTOCOL
(FTP)
:

Allows file
transfer on Internet

*


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INTERNET


NETWORK OF NETWORKS THAT USE
THE
TCP/IP

PROTOCOL, WITH
GATEWAYS (CONNECTIONS) TO OTHER
NETWORKS THAT DO NOT USE TCP/IP


INTERNET APPLICATIONS:

e
-
mail,
Usenet newsgroups, listserv,
FTP
,
Gopher, Archie, Veronica, World Wide
Web

*


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CONNECTIONS TO INTERNET


PHONE LINE MODEM


CABLE MODEM


DIGITAL SUBSCRIBER LINE
(DSL)


T
-
1 DATA PHONE LINE


SATELLITE


FIBER OPTICS

*


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INTRANET


A NETWORK OPERATING WITHIN AN
ORGANIZATION EMPLOYING TCP/IP
PROTOCOL


ORGANIZATION USES SAME WEB
BROWSER, CRAWLER, SERVER
SOFTWARE AS IT WOULD ON THE
INTERNET, BUT INTRANET IS NOT
ACCESSIBLE FROM OUTSIDE THE
ORGANIZATION

*


© Prentice Hall 2002

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CONNECTIVITY


MEASURE OF ABILITY OF
COMPUTING DEVICES TO PASS &
SHARE INFORMATION WITHOUT
HUMAN INTERVENTION


OPEN SYSTEMS:
Software able to
function on different computer
platforms. Nonproprietary operating
systems, applications, protocols

*


© Prentice Hall 2002

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INTERNET 2


WILL REPLACE INTERNET


LEADING
-
EDGE NETWORK CAPABILITY


HIGH
-
PERFORMANCE APPLICATIONS


RAPID TRANSFER OF SERVICES,
APPLICATIONS TO BROADER INTERNET
COMMUNITY

*


© Prentice Hall 2002

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CHAPTER 4

Telecommunications &
Networking